Until Apple changes the model for how effects work, it's worth investigating Andreas' free Motion Template Tool. As well as being able to install templates into different user accounts, it can also inspect FCPXML and collect required effects in one place alongside an install script.

Don't know if this would help, but we are using an app called "FolderWatch" to sync templates between our edit machines and our file server. It takes a moment to setup for each user but works very well and is just $10: